DE102004034830A1 - Deflection roll - Google Patents

Abstract

A deflection compensating roller including a rotating roller casing, a rotationally fixed yoke axially extending through the roller casing, at least one hydrostatic support device arranged between the yoke and the roller casing, the at least one hydrostatic support device comprising a pressure compartment and at least one oil pocket that communicates with the pressure compartment via at least one first restricted flow zone and at least one second restricted flow zone, and a fluid comprising at least one of an electrorheological fluid (ERF) and a ferro fluid. A viscosity of the fluid is adapted to be varied by way of one of an electric and magnetic field. This abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

Description

The The invention relates to a bending compensating roll having a peripheral Roll shell, a roll jacket axially passing through a rotationally fixed yoke and at least one disposed between the yoke and the roll shell hydrostatic source of support, the on its side facing the roll shell at least one oil bag that has over at least one first throttle point with the pressure chamber of the support source communicates.

In Such bending compensating rollers are used for supporting sources which be acted upon by a supply line with oil pressure. This oil pressure presses the support source against the rotating roll shell. Since the piston surface of the support source is smaller than the roller shell facing pocket surface, provides a lesser pocket oil pressure one. The pressure difference between piston pressure and pocket pressure determined the volume flow over the capillaries are flowing, the between the pocket area and the piston surface are switched. Thus, depending on the piston pressure of Volume flow at a support source one.

to individual profile correction of the current through the nip Goods are the sources of support individually with an oil pressure applied. The height the oil pressures is over a Online profile thickness measurement of the web regulated. Dependent on from the necessary profile corrections, it can now but to large oil pressure differences at the sources of support (e.g., 3.5 to 90 bar from source to source).

This leads, As already mentioned, to volume flow differences at the support sources. Between the rotating Roll shell and the support sources is caused by the oil shear dependent on of the shell velocity and the oil gap height, again from the volume flow, the oil temperature and the pocket pressure is, friction. By the big ones Pressure differences thus arises from one source to another a different level of friction, resulting in temperature differences on the roll shell. These temperature differences have in turn an effect on the shape of the roll shell and thus a feedback effect on the generating line load profile of the bending compensating roll.

There at a pressure relief at a support source, the lower flow rate adjusts, results in this support source despite lower in amount Frictional loss as at high pressures a higher one Temperature. A higher one Temperature leads but now to an extension of the roll shell, which is in a Line load increase in the nip. The relevant temperature development extremely so in opposite directions to the desired Pressure relief and is therefore undesirable. In individual cases can it even causes instability lead the control behavior.

So far it was common practice the temperature development at the support sources by a separate cooling flow to limit, which is passed into the interior of the roller. For this was a low temperature volume flow, the amount of which over the Return temperature the roller is controlled by nozzles in the roller interior distributed. Through this distribution, each support source is supplied with the same amount of cooling oil. By the volume flow differences described above are in spite of the supplied Cooling oil amount different Temperatures at the sources of support. The self-adjusting mixing temperature in the roll interior corresponds in about the local Return temperature.

The settling local Return temperatures show with decreasing cooling oil flows one increasing temperature difference between a highly loaded and low loaded source of support. This temperature difference will significantly affect the shape of the rotating Impact roll jacket.

From the DE 101 36 270 A A deflection-adjusting roll is already known in which the quantity of fluid locally supplied to a respective rolling zone by means of a temperature-influencing device can be varied as a function of the piston pressure of the respective support element or support element group.

Of the Invention is based on the object, an improved bending compensating roll of the type mentioned above, in which the aforementioned Disadvantages are eliminated.

According to the invention this object is achieved by a bending compensating roll with a rotating roll shell, a roll jacket axially passing through the non-rotatable yoke and at least one arranged between the yoke and the roll shell hydrostatic support source having on its side facing the roll shell at least one oil pocket over at least a first Throttle is in communication with the pressure chamber of the support source, wherein the support source is at least partially operated with an electrorheological fluid (ERF) and / or ferrofluid whose viscosity is variable via an electric or magnetic field, and wherein the oil pouch over at least one of the first Throttle parallel second throttle Le is in communication with the pressure chamber and the flowing through the second throttle additional volume flow over a viscosity of the electrorheological fluid (ERF) or ferrofluid influencing field is variable.

by virtue of This training can therefore the flowing through the second throttle additional volume flow for one desired Temperature control can be varied accordingly. Unwanted temperature influences can do so repressed or be compensated. The fact is exploited that the flow characteristic or viscosity an electrorheological fluid or ferrofluid under the influence of an electric or magnetic field, i. for example a volume flow through change of the field in question can be varied.

Under The influence of the relevant field can affect the flow properties the electrorheological fluids (ERF) or ferrofluids continuously and reversibly changed become. At the today available ER fluids it is in particular silicone oil, in the polyurethane particles are dispersed. With increasing electrical voltage or field strength decreases the apparent viscosity the ERF in the field too and the volumetric flow off. The properties of a electrorheological fluid (ERF) or ferrofluids thus allow For example, a relatively simple, fast and always fail-safe Flow control. About that beyond is over a corresponding variation in the viscosity of the electrorheological Fluids or ferrofluids in particular also a support source pressure control conceivable. In addition, you can targeted specific damping properties at the source of support realized or even the leadership behavior the roll shell can be influenced in a targeted manner.

Prefers is the flowing through the second throttle additional volume flow over the relevant Field in dependence variable by the pressure in the pressure chamber.

there is the flowing through the second throttle additional volume flow over the concerned in particular so controllable and / or controllable that at higher To press in the pressure chamber a lesser or no additional volume flow and at lower pressures in the pressure room a higher additional Volume flow results. In the case that at higher pressures no additional Volume flow more flows, becomes the relevant source of support like a conventional one support source operated. In contrast, flows at low piston pressures additional Volume flow over the source of support, what an increase of the oil slit brings with it and thus to a reduction of the frictional loss leads.

With the lower friction and the increased volume flow results a significant reduction in the resulting oil temperature in the return, whereby the aforementioned negative thermal effects are avoided.

The inventive parallel circuit a fixed throttle and one electrically or magnetically controllable throttling point also brings with it the advantage that in case of possibly occurring faulty operations of the controllable throttle point it does not cause a mixed friction between the support sources and the rotating one Roll shell can come. At completely closed electrically or magnetically controllable throttle points becomes the functionality the support sources unchanged receive.

at a convenient practical embodiment the bending compensating roll according to the invention, at the source of support operated at least partially with an electrorheological fluid (ERF) is, is the flowing through the second throttle additional Volume flow over an electric field variable. In this case, in the second Throttle for generating the electric field an electrical Be arranged conductor, cable or the like.

advantageously, is over a the viscosity of the electrorheological fluid (ERF) or ferrofluid influencing Field especially the hydraulic pressure or pressure in the pressure chamber variable. In particular, a pressure control can be provided be.

Basically, over a the viscosity of the electrorheological fluid (ERF) or ferrofluid influencing Field in particular also the flowing through the first throttle flow rate be variable. Again, in particular, a flow control be provided.

It Now, for example, such embodiments of the bending compensating roll conceivable in which the source of support exclusively is operated with the electrorheological fluid or ferrofluid.

there can several sources of support over one common supply line with the electrorheological fluid (ERF) or ferrofluid, in which the system pressure (e.g. Pump pressure) is maintained.

Between the pressure chamber of a respective support source and the common supply line is preferably provided in each case a connecting line, in which a throttle point is integrated, in which for generating the field, for example a electrical conductor, cable or the like is arranged.

While the viscosity a respective electrorheological fluid (ERF) usually via an electrical Field or an electrical voltage is changeable, is with the likewise Ferrofluids used the viscosity by the onset of a corresponding magnetic field changeable.

The Invention will be described below with reference to an embodiment with reference closer to the drawing explained.

In this drawing, the single figure shows a schematic, partial sectional view of an exemplary embodiment of a bending compensating roll 10 that has a circumferential roll shell 12 and a roll jacket 12 axially penetrating non-rotatable yoke 14 and at least one between the yoke 14 and the roll shell 12 arranged support source 16 includes.

In the present case, the source of support is 16 operated exclusively with an electrorheological fluid (ERF) or ferrofluid whose viscosity is variable via an electric or magnetic field.

In this case, among other things, the hydraulic pressure can be varied via the field influencing the viscosity of the electrorheological fluid (ERF) or ferrofluid, with pressure regulation in particular being able to be provided. There are several, preferably all sources of support 16 via a common supply line 18 supplied with the electrorheological fluid (ERF) or ferrofluid, in which the system pressure (eg pump pressure) is maintained.

Between the pressure room 20 a respective support source 16 and the common supply line 18 is in each case a connecting line 22 intended. In this connection line 22 is a throttle point 24 integrated, in the generation of the field, an electrical conductor 26 , a coil or the like is arranged.

There is also a direct with the pressure room 20 the source of support 16 connected pressure transducer 28 intended.

The intended for pressure control electrical controller is preferably outside the roller 10 arranged.

In the present case, therefore, preferably each support source 16 operated exclusively with the electrorheological fluid (ERF) or ferrofluid. The pressure is supplied via the common supply line 18 for all sources of support or supporting elements 16 in which the system pressure (for example, pump pressure) is maintained. In the connection line 22 to the pressure room 20 a respective support source 16 is the throttle point 24 integrated, in the means of the electrical conductor 26 , Coil or the like the field in question can be constructed. In the present case, an electric field is generated or a voltage applied, ie, the viscosity of an electrorheological fluid (ERF) is influenced accordingly here. As mentioned, however, it is also possible, for example, to use a ferrofluid whose viscosity can then be correspondingly influenced via a corresponding magnetic field.

For controlling the hydraulic pressure under the support source 16 becomes the actual pressure with the pressure transducer 28 detected, which may be formed by a commercially available pressure transducer. For pressure control of a support source 16 are thus inside the bending compensating roll 10 only the throttle point 24 For example, with insulated power connection, two cables and a pressure transducer 28 required.

As can be seen from the single figure, has the hydrostatic support source 16 on her the roll mantle 12 facing side at least one oil pocket 30 on, which has at least a first throttle point 32 with the pressure room 20 the source of support 16 communicates. In the only figure are two such oil pockets 30 to recognize.

There is a respective oil bag 30 via at least one to the first throttle point 32 parallel second throttle point 34 with the pressure room 20 connected. The through a respective second throttle point 34 flowing additional volume flow is now also variable over the viscosity of the electrorheological fluid (ERF) or ferrofluid influencing field.

In this case, by the second throttle point 34 flowing additional volume flow over the field in question, in particular as a function of the pressure in the pressure chamber 20 be variable. It is the second throttle point 34 flowing additional volume flow over the field in particular so taxable and / or regulated that at higher pressures in the pressure chamber 20 a lower or no additional volume flow and at lower pressures in the pressure chamber 20 a higher additional volume flow results.

In the present embodiment, an electric field is again generated or a voltage applied, ie it is here again the viscosity of an electrorheological fluid (ERF) ent influenced by speaking. In a respective second throttle 34 So, for example, each again an electrical conductor 36 or the like may be provided to generate the respective electric field.

As already mentioned, however, it is also possible, for example, to use a ferrofluid whose viscosity can then be correspondingly influenced via a corresponding magnetic field. In the second throttle points 34 is then in each case a coil or the like to use, over which the magnetic field in question is generated.

to suppression undesirable temperature influences can so sources of support, which are flowed through by an electrorheological fluid or ferrofluid, be particularly easily transformed or further educated. Next the usual Capillary bores (first throttle) is at least a second for each oil pocket Throttle connected in parallel, through which an additional flowing volume flow by connecting an electric or magnetic field preferably depending on upcoming piston pressure can be controlled.

at high piston pressures is at the parallel-connected second throttle bodies, for example a Voltage applied that is so high that no or only a small one Amount of electrorheological fluid through the second orifices flows. In this case, the support source like a conventional source of support operated.

at low piston pressures a lower voltage is applied, so that an additional volume flow over the support source flows. this leads to to an increase of the oil slit and thus to a reduction of the frictional loss.

by virtue of the lower friction and the increased volume flow results a significant reduction in the resulting oil temperature in the return, whereby the aforementioned negative thermal effects are avoided.

The Parallel connection of a fixed throttle point and an electrical or magnetically controllable throttle body brings with it the advantage itself, that in case of possible Fehlbeaufschlagungen the controllable Do not restrict it to a mixed friction between the support sources and the rotating roll shell can come. In completely closed, for example, electrically or magnetically controllable second throttle points becomes the functionality the support sources unchanged receive.

10

Deflection roll

12

roll shell

14

yoke

16

support source

18

supply line

20

pressure chamber

22

connecting line

24

restriction

26

electrical ladder

28

Pressure transducer

30

oil pocket

32

first restriction

34

second restriction

36

ladder

Claims (12)

Bend compensation roller ( 10 ) with a peripheral roll shell ( 12 ), a roll shell ( 12 ) axially penetrating non-rotatable yoke ( 14 ) and at least one between the yoke ( 14 ) and the roll shell ( 12 ) arranged hydrostatic support source ( 16 ), which are on their 12 ) facing side at least one oil bag ( 30 ), which via at least one first throttle point ( 32 ) with the pressure chamber ( 20 ) of the support source ( 16 ), the source of support ( 16 ) is operated at least partially with an electrorheological fluid (ERF) and / or ferrofluid whose viscosity is variable via an electric or magnetic field, and wherein the oil pocket ( 30 ) via at least one to the first throttle point ( 32 ) parallel second throttle point ( 34 ) with the pressure chamber ( 20 ) and that through the second throttle restriction ( 34 ) flowing additional volume flow over a the viscosity of the electrorheological fluid (ERF) or ferrofluid influencing field is variable. Bending compensation roller according to claim 1, characterized in that the through the second throttle point ( 34 ) flowing additional volume flow over the field in question as a function of the pressure in the pressure chamber ( 20 ) is variable. Bending compensation roller according to claim 2, characterized in that the through the second throttle point ( 34 ) flowing additional volume flow over the field in question is controlled and / or regulated so that at higher pressures in the pressure chamber ( 20 ) a lower or no additional volume flow and at lower pressures in the pressure chamber ( 20 ) gives a higher additional volume flow. Bending compensation roll according to one of the preceding claims, characterized in that the support source ( 16 ) at least partially with egg operated by an electrorheological fluid (ERF) and by the second throttle point ( 34 ) flowing additional volume flow through an electric field is variable. Bend compensating roller according to claim 4, characterized in that the second throttle point ( 34 ) comprises an electrical conductor, cables and / or the like. Bend compensation roller according to one of the preceding Claims, characterized in that over a the viscosity of the electrorheological fluid (ERF) or ferrofluid influencing Field of hydraulic pressure or pressure in the pressure chamber is variable. Bending compensation roll according to claim 6, characterized in that that a pressure control is provided. Bending compensating roll according to one of the preceding claims, characterized in that the field influencing the viscosity of the electrorheological fluid (ERF) or ferrofluid by the first throttling point ( 32 ) flowing volume flow is variable. Bending compensation roll according to claim 8, characterized in that that a volume flow control is provided. Bending compensation roll according to one of the preceding claims, characterized in that the support source ( 16 ) is operated exclusively with the electrorheological fluid (ERF) or ferrofluid. Bending compensation roll according to one of the preceding claims, characterized in that a plurality of support sources ( 16 ) via a common supply line ( 18 ) are supplied with the electrorheological fluid (ERF) or ferrofluid, in which the system pressure is maintained. Bend compensating roller according to claim 11, characterized in that between the pressure chamber ( 20 ) of a respective support source ( 16 ) and the common supply line ( 18 ) each a connecting line ( 22 ) is provided, in which a throttle point ( 24 ) is integrated, in which for generating the field, a preferably electrical conductor ( 26 ), Cables or the like is arranged.